CHICAGO (CBS) -- The circumstances surrounding Monday's collision on the CTA's Blue Line were so unusual that police at first suspected it had to be a deliberate, criminal act.
How Did This Happen
What other way to explain how a train could leave a rail yard, drive past one station terminal and travel at least a mile down the wrong tracks without safety mechanisms stopping the cars before the crash?
It appears that's exactly what happened.
"The million dollar question is, how did this happen?" said Robert Kelly, of Amalgamated Transit Union 308. Kelly said somebody would need to use a key to power up and drive the rail cars.
Witnesses reported that the four-car train, traveling eastbound before smashing into a standing westbound train at Harlem Avenue in Forest Park, did not have a driver and CTA officials said video showed no one was operating the train during the crash. Some have dubbed it a "ghost train."
Potentially complicating the investigation, Kelly tells CBS 2, is word that cameras stationed where the train began its mysterious journey were not functioning Monday morning.
Tim DePaepe, the lead investigators with the National Transportation Safety Board, is still trying to figure out how the empty Blue Line train ended up on the tracks.
"I want to establish that the signal system worked as it is designed. That is the first thing we want to rule out. Then you want to rule out mechanical issues. If it is not signal, it is not mechanical, then you look at operations. Because then it might be a human factor accident," said DePaepe.
DePaepe said the agency was in the process of downloading video tapes and signal data. He said it was too early to determine a probable cause.
According to the CTA, that train was marked "Out Of Service" when it began its mysterious ride out of the Forest Park rail yard, where the Blue Line begins in the western suburb.
The train traveled out of the yard and past the Forest Park station stop before traveling eastbound to the next station at Harlem.
The four-car runaway train which struck the standing westbound train filled with passengers at the Harlem Avenue station, was scheduled to go the CTA's Skokie workshop to repair cars 3 and 4, which had been out of service since last Monday.
"We were standing still and then all of a sudden something hit us and I got shot forward into the front seat," said one passenger as she limped to a responding ambulance.
Kelly told CBS 2 the train may have been traveling upwards of 20 to 25 miles per hour when it hit the stationary train.
What is clear: Several fail-safe mechanism failed to work properly.
Another (one of many) key question: How did the eastbound train manage to leave the Forest Park rail yard and pass over at least two interlocking systems that should have triggered the brakes?
"There were two switches that ideally should have stopped the train, but they did not. Now that could have been a simple matter of those switches being misaligned or not set properly in the first place so we do have fail safes in place however they didn't function the way they should in this particular case," said CTA Spokesman Brian Steele.
It may have been the other train, which, when it entered the Harlem station, automatically triggered a clear track through to Forest Park, obviously unaware there was a train coming the other way on the same track. Still, there was one fail safe feature left. It's called the dead man's switch, alerting of a collision course, and stopping the train.
"If that train's is keyed up and someone is operating that train they actually have to press a button to override that. We know there's no one in the train as of right now so I don't know how this happened," said Robert Kelly, of Amalgamated Transit Union 308.
The conductor of the westbound train saw the approaching train and did what he could to alert passengers to take over or brace themselves for impact.
CBS 2's Jay Levine reports that the motorman of the Harlem train got a message and ran into the first car telling the passengers "hold on, hold on" just before the runaway train, with no one at the controls, crashed into their train.
That conductor walked away from the accident, but did have some facial injuries.
As of 11 a.m., Forest Park police were still investigating and CTA officials had not yet begun their investigation.
CTA spokesman Brian Steele said that the train was not going very fast and that CTA is operating under the theory that the accident was due to a mechanical malfunction.
"At CTA safety is our top priority, which is why we are very concerned about this accident," said CTA president Forrest Claypool.
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